Civilizations have made a variety of ceramic articles such as cooking and serving vessels, water and other fluid containers, tiles, bricks, etc., for thousands of years. These were typically coloured or decorated with metal oxide type pigments that developed colours or more intense colours during an elevated temperature firing of the pigment and ceramic article. The metal oxide type colouration pigments were thought to chemically interact and interpenetrate and develop colours at high temperatures with the ceramic composition and/or with more glassy compositions sometimes applied with the colouration pigments or subsequently applied. The more glassy compositions were often to provide impermeable or barrier properties to the outer surface of the ceramic article (to protect the ceramic article from environmental materials with which it might come into contact).
With conventional organic pigments and the few inorganic pigments (e.g., TiO2, silica, and talc) in polymeric organic binder, the particle size and particle uniformity are very important to achieve consistent and intense colouration. Inorganic mixed metal oxide pigments used in inorganic ceramic colouration are generally not as well understood as organic pigments. The particle size of the inorganic mixed metal oxide pigments generally has not been studied and controlled to the extent that particle sizes of pigments has been controlled for use in polymeric organic coatings and inks.
U.S. Pat. No. 3,846,127 discloses an imaging system comprising photosensitive pigment dispersed in an insulating binder and exposed to actinic electromagnetic radiations. The pigment particles are treated with polyisobutylsuccinic anhydride or derivatives thereof before being incorporated in the imaging layer.
WO87/05924 discloses dispersions of solids in organic liquids where the dispersant has a molecular weight from 500 to 10,000. The solids can be inorganic or organic pigments. The use can be in paints, enamels, printings inks and other surface coatings, including articles made from plastics and rubber. Examples 1-13 include polyisobutylene based dispersants.
US 2008/0182927 discloses PIBSAs as dispersants for metal oxide nanoparticles in liquid including toluene, xylene, mineral spirits, hexanes, and phenoxyisopropanol. The metal oxides mentioned by name include those of zinc, zirconium, cerium titanium, aluminum, indium and tin. In their examples, they used alumina with a particle size of 30 nm, zirconia with a particle size of 15 nm, ceria with a particle size slightly less than 100 nm, and zinc oxide with a particle size of 30 nm.